Method for manufacturing semiconductor device

ABSTRACT

A method of separating a lamination body with high yield without damaging the lamination body is provided. Further, a method of manufacturing a lightweight, flexible semiconductor device, which is thin in total is provided. The method of manufacturing the semiconductor device includes: a first step of laminating a metal layer, an oxide layer, a layer containing no hydrogen element, and a lamination body on a first substrate; a second step of forming a photocatalytic layer on a transparent substrate; and a third step of attaching the photocatalytic layer to the surface of the lamination body by using a first adhesive material after the first and second steps, separating the metal layer from the oxide layer, and irradiating light from a side of the transparent substrate so that an interface between the photocatalytic layer and the first adhesive material is separated to remove the first adhesive material.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of separating (or peeling) alamination body and a method of manufacturing a semiconductor deviceformed using a plastic substrate.

2. Description of the Related Art

In recent years, a technique of forming a thin film transistor (TFT)using a semiconductor thin film (with a thickness of from approximatelyseveral nm to several hundreds nm), which is formed over a substratewith an insulated surface, has been attracting attention. The thin filmtransistor has been widely applied in various electronic devices such asan IC and a display device. In particular, development related to thethin film transistor as a switching element for an image display devicehas been carried out hurriedly.

Various applications of such an image display device have been expected,and particularly, application to a portable device has been attractingmuch attention. A glass substrate and a quartz substrate has beentypically used for forming the image display device now, however, thesesubstrates have some drawbacks of being fragile and heavy. Further,these substrates are unsuitable for mass-production since the surfacearea thereof is difficulty enlarged. Therefore, it has been tried toform a semiconductor element, e.g., a TFT on a substrate havingflexibility as typified by a flexible plastic film.

In the case of using the flexible plastic substrate, however, themaximum temperature of the process should be lowered since the plasticfilm has low heat resistant properties. Accordingly, it has beenimpossible to form a semiconductor element, e.g., a TFT having as goodelectric characteristics as that formed over a glass substrate. Thus, ahigh-performance semiconductor device, e.g., a liquid crystal displaydevice or light emitting element using a plastic film has beendeveloped.

Various kinds of methods for separating a lamination body, which isformed over a substrate through a separation body, from the substratehave been already proposed. For example, there is a technique asdisclosed in patent document 1 and patent document 2, wherein aseparation layer is formed on a transparent substrate by using amorphoussilicon (or polysilicon), a lamination body is formed thereon, and laserlight is irradiated from a side of the substrate to discharge hydrogencontained in the amorphous silicon so that a gap is caused between theseparation layer and the substrate and the substrate is separated fromthe lamination body.

[Patent Document 1]: Japanese Patent Application Laid-Open No. Hei10-125929

[Patent Document 2]: Japanese Patent Application Laid-Open No. Hei10-125931

In the above-mentioned separation method, however, a substrate having ahigh light-transmitting property is absolutely required. Further, a stepfor irradiating relatively high-energy laser beam on an entire surfaceof the substrate is required to apply sufficient energy such that laserbeam transmits through the substrate and hydrogen contained in theamorphous silicon is discharged. This might damage the lamination body.In the case where an element is formed on the separation layer accordingto the above-mentioned separation method, when the element is formed bya heat treatment at high processing temperatures, hydrogen contained inthe separation layer is dispersed and reduced. Accordingly, poorseparation might be caused even when laser beam is irradiated to theseparation layer, which results in reduced yield.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a separation method withhigh yield without damaging a lamination body. It is another object ofthe invention to provide a method of manufacturing a lightweight,flexible semiconductor device that is entirely thin.

According to one aspect of the invention, there is provided a method ofmanufacturing a semiconductor device that includes: a first step oflaminating a metal film, an oxide film, a film containing no hydrogenelement, a lamination body on a first substrate; and a second step offorming a photocatalytic layer on the surface of a transparentsubstrate; a third step of attaching the photocatalytic layer to thesurface of the lamination body by using a first adhesive material afterthe first and second steps, separating (or peeling) the metal film fromthe oxide film, and irradiating light from a side of the transparentsubstrate so that an interface between the photocatalytic layer and thefirst adhesive material is separated (or peeled).

After the third step, a fourth step for removing the first adhesivematerial may be performed.

Since the film containing no hydrogen element is formed on the oxidefilm, the oxide film is not reduced in a heat treatment, which will becarried out in a step of manufacturing a semiconductor element later,and hence, the metal film can be separated from the oxide film by asmall force. The film containing no hydrogen element is hereinafterreferred to as an anti-reduction film (or a film for preventingreduction).

When the film containing no hydrogen element has a conductive property,it can be formed as a connection terminal as follows: after removing theoxide film, the film containing no hydrogen element is etched in apredetermined shape to achieve the connection terminal.

Alternatively, when the film containing no hydrogen element has aninsulating property, a connection terminal is formed as follows: theoxide film and the film containing no hydrogen element are etched in apredetermined shape to form a protective film while exposing a part of aconductive film that is provided in the lamination body, so as toachieve the connection terminal.

Further, after separating the metal film from the oxide film, a secondsubstrate can be attached to a surface of the oxide film by using asecond adhesive material.

The metal film is made from an element selected from titanium, aluminum,tantalum, tungsten, molybdenum, copper, chromium, neodymium, iron,nickel, cobalt, ruthenium, rhodium, palladium, osmium, and iridium; asingle layer formed of an alloy material or a compound materialcontaining the above-mentioned elements as its main constituent; or alamination layer thereof.

The oxide film is formed by subjecting the metal film to a thermaloxidation treatment, a plasma irradiation treatment, or a treatmentusing a strong oxidizing solution.

The film containing no hydrogen element is a nitride of an elementselected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, Fe, Co, Mn, Ni, and Al bysputtering.

As examples for the semiconductor device according to the invention, adisplay device, a function circuit, and the like can be cited.Typically, a liquid crystal display device, a light emitting displaydevice, a DMD (digital micromirror device), a PDP (plasma displaypanel), an FED (field emission display), an electrophoretic displaydevice (an electronic paper), and the like can be cited as the displaydevice. The function circuit includes a CPU (central processing unit), aDRAM (dynamic random access memory), an image processing circuit, anaudio processing circuit, a driver circuit, and the like.

According to the invention, separation can be performed at high yieldwithout damaging a lamination body. A semiconductor device having asemiconductor element can be formed on a plastic substrate. As aconsequence, a lightweight, thin semiconductor display device with anexcellent impact resistance property can be manufactured. In addition, asemiconductor device having a curved surface or a semiconductor devicethat can be varied in shape can be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A to 1E are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the present invention;

FIGS. 2A to 2E are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the invention;

FIGS. 3A to 3E are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the invention;

FIGS. 4A to 4D are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the invention;

FIGS. 5A to 5D are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the invention;

FIGS. 6A to 6E are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the invention;

FIGS. 7A to 7E are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the invention;

FIG. 8 is a cross sectional view showing a structure of a semiconductordevice according to the invention;

FIGS. 9A to 9D are cross sectional views explaining steps ofmanufacturing a semiconductor device according to the invention;

FIGS. 10A and 10B are diagrams showing structures of light emittingelements;

FIGS. 11A to 11C are circuit diagrams of pixels for light emittingelements;

FIG. 12A is a top view and FIG. 12B is a cross sectional view explaininga semiconductor device according to the invention;

FIG. 13A is a top view and FIG. 13B is a cross sectional view explaininga semiconductor device according to the invention;

FIG. 14A is a top view and FIG. 14B is a cross sectional view explaininga semiconductor device according to the invention;

FIG. 15A is a top view and FIG. 15B is a cross sectional view explaininga semiconductor device according to the invention;

FIG. 16 is a block diagram explaining a structure of an electronicappliance;

FIG. 17 is a perspective view showing an example of an electronicappliance;

FIGS. 18A and 18B are perspective views showing an example of anelectronic appliance; and

FIGS. 19A to 19D are diagrams showing examples of implementing a methodfor mounting a semiconductor device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION Embodiment Mode 1

In the present embodiment mode, a method of separating a lamination bodyformed over a substrate will be described with reference to FIGS. 1A to1E.

As shown in FIG. 1A, a metal film 102 is formed on a first substrate101. As the first substrate, a heat-resistant substrate, i.e., amaterial that can withstand the heat treatment in a step ofmanufacturing an optical filter formed later and the separation step,typically, a glass substrate, a quartz substrate, a ceramic substrate, asilicon substrate, a metal substrate, or a stainless substrate can beused.

The metal film 102 may be formed of an element selected from titanium(Ti), aluminum (Al), tantalum (Ta), tungsten (W), molybdenum (Mo),copper (Cu), chromium (Cr), neodymium (Nd), iron (Fe), nickel (Ni),cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os),iridium (Ir); a single layer formed of an alloy material containing theabove-mentioned elements as its main constituent; or a lamination layerthereof. Conditions of the subsequent separation step can be varied byadjusting a composition ratio of metal in alloy for the first metal filmor a composition ratio of oxygen or nitrogen contained therein,properly. Therefore, the separation step can be adapted to various typesof processing. The metal film 102 is formed by a known formation methodsuch as sputtering, CVD, and vapor deposition to have a thickness of 10to 200 nm, preferably, 50 to 75 nm.

An oxide film 103 is formed on the metal film 102. The surface of themetal film 102 is subjected to a thermal oxidation treatment, an oxygenplasma treatment, a treatment using a strong oxidizing solution such asozone water to form the oxide film 103 with a thickness of 1 to 10 nm,preferably, 2 to 5 nm.

In the case of the separation step carried out later, separation iscaused inside the oxide film or in an interface between the metal filmand the oxide film.

An anti-reduction film 104 is formed on the oxide film 103. It ispreferable that a film, that substantially contains no hydrogen element,be used as the anti-reduction film. Therefore, the present embodimentmode uses a film containing no hydrogen element. That is, theanti-reduction film 104 is the film containing no hydrogen element. Asrepresentative examples of the anti-reduction film, nitride of anelement selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, Fe, Co, Mn, Ni, andAl, and the like. In the present embodiment mode, the anti-reductionfilm is formed by sputtering with use of a target including theabove-mentioned element along with nitrogen. For example, an aluminumnitride (AlN) target is employed.

By using the anti-reduction film, it is possible to prevent reduction ofthe oxide film 103 in the heat treatment for a lamination body that willbe performed later.

A lamination body 105 is formed on the anti-reduction film 104. Thelamination body is formed by arbitrarily combining a semiconductorelement (such as a thin film transistor, an organic thin filmtransistor, a thin-film diode photoelectric conversion element, and aresistive element), a display element (such as a liquid crystal element,a light emitting element, a pixel electrode, a micromirror array, and anelectron emitter).

A photocatalytic layer 112 is formed on a surface of a transparentsubstrate 111. As the photocatalytic layer, titanium oxide (TiO_(x)),titanate (MTiO₃), tantalate (MTaO₃), niobate (M₄Nb₆O₁₇), Cds, ZnS, andthe like can be cited (note that every “M” indicates a metal element).These materials are formed by sputtering, plasma CVD, vapor deposition,sol-gel, reversed phase micelle, electrophoresis, etc. so as to achievethe photocatalytic layer. As the transparent substrate 111, followingscan be used: a glass substrate; a quartz substrate; a plastic substratehaving a light transmitting property (e.g., polycarbonate (PC), ARTONformed of a norbornene resin with a polar radical that is manufacturedby JSR Corporation, polyethylene terephthalate (PET), polyether sulfone(PES), polyethylene naphthalate (PEN), nylon, polyether ether ketone(PEEK), polysulfone (PSF), polyetherimide (PEI), polyarylate (PAR),polybutylene terephthalate (PBT), polyimide, etc.); and the like.

As shown in FIG. 1B, the lamination body 105 and the photocatalyticlayer 112 are attached to each other by using a first adhesive material113 formed of an organic resin. As for the first adhesive material 113,organic resins such as an epoxy resin, a silicon resin, and an acrylicresin can be exemplified. When using an oil-soluble adhesive materialetc., a subsequent separation step can be easily performed. In the casewhere the first adhesive material is formed by application, the appliedadhesive material will serves as a planarizing film. Therefore, asubstrate can be attached thereto such that a surface of the substrateis approximately parallel to a surface of the planarizing film.

Preferably, a support medium is attached to the first substrate 101 byusing a peelable adhesive agent to prevent breakage of each substrate.By attaching the support medium thereto, the subsequent separation stepcan be carried out easily by a smaller force. A substrate with higherrigidity than that of the first substrate, typically, a quartzsubstrate, a metal substrate, a ceramic substrate, etc. are preferablyused as the support medium.

As shown in FIG. 1C, the metal film 102 is separated from the oxide film103 by a physical means. The physical force indicates, for example, arelatively small force such as hand power, gas pressure applied througha nozzle, ultrasonic waves, and load using a wedge-shaped member.

Consequently, separation is caused inside the oxide film 103 or in aninterface between the metal film 102 and the oxide film 103 so that theoxide film 103, the anti-reduction film 104, the lamination body 105,and the transparent substrate 111 attached to the lamination body can beseparated from the first substrate 101 by a relatively small force.

To separate easily, a pretreatment is preferably carried out as aprevious step prior to the separation step. Typically, a treatment forpartly reducing the adhesiveness between the metal film 102 and theoxide film 103 is performed. The treatment for partly reducing theadhesiveness therebetween is performed by partly irradiating laser beamto the metal film 102 along a rim of a region to be separated, orperformed by partly damaging inside or an interface of the metal film102 by locally applying pressure along a rim of a region to be separatedfrom an external portion. Specifically, a hard needle such as a diamondpen may perpendicularly be pressed and moved while applying loadthereto. A scriber device is preferably used to move the hard needlewhile applying pressure with press force of from 0.1 to 2 mm.Accordingly, it is important to generate a portion where a separationphenomenon is easily caused, i.e., a trigger of the separationphenomenon, prior to performing the separation step. By performing thepretreatment for selectively (partly) reducing the adhesiveness inadvance, poor separation can be prevented, thereby improving the yield.

As shown in FIG. 1D, light 123 is irradiated from a side of thetransparent substrate 111. The light 123, which can activate thephotocatalytic layer, may be used. In the case where the photocatalyticlayer is formed of TiOx, ultraviolet light may be irradiated. When thephotocatalytic layer is formed of CdS, visible light may be irradiated.Irradiation of light allows the photocatalytic layer to be separatedfrom the first adhesive material 113.

Subsequently, as shown in FIG. 1E, the transparent substrate 111 and thephotocatalytic layer 112 formed thereon are removed. Also, the firstadhesive material 113 may be removed.

According to the above-mentioned steps, the lamination body including asemiconductor element that is formed on the first substrate can beseparated. A semiconductor device comprising a lamination body formed onthe oxide film and the anti-reduction film can be manufactured. Byutilizing only the oxide film and the anti-reduction film as supportmediums, a thin, lightweight, flexible semiconductor device can bemanufactured. Such a semiconductor device can be attached or disposed toa predetermined portion, and hence, can be applied widely.

Embodiment Mode 2

A method of manufacturing a semiconductor device using a plasticsubstrate as its support medium will be described in the presentembodiment mode with reference to FIGS. 2A to 2E.

As shown in FIG. 2C, a metal film 102 is separated from an oxide film103 in the same manner as the steps illustrated in FIGS. 1A to 1C inEmbodiment Mode 1.

As shown in FIG. 2D, a second substrate 121 is attached to a surface ofthe oxide film 103, where is exposed due to the separation, by using asecond adhesive material 122. As for the second adhesive material, anepoxy resin can be used. The second substrate can be made from anorganic resin such as polycarbonate (PC); ARTON formed of a norborneneresin with a polar radical that is manufactured by JSR Corporation;polyethylene terephthalate (PET); polyether sulfone (PES); polyethylenenaphthalate (PEN); nylon; polyether ether ketone (PEEK); polysulfone(PSF); polyetherimide (PEI); polyarylate (PAR); polybutyleneterephthalate (PBT); polyimide; polypropylene; polypropylene sulfide;polyphenylene sulfide; polyphenylene oxide; polysulfone; andpolyphthalamide. In addition, an HT substrate (manufactured by NipponSteel Chemical Co., Ltd.) with a Tg (glass transition) point of 400° C.or more may be used.

Light 123 is irradiated from a side of a transparent substrate 111 aswell as Embodiment Mode 1. According to the irradiation step, thephotocatalytic layer 112 is separated from the first adhesive material113.

As shown in FIG. 2E, the transparent substrate 111 and thephotocatalytic layer 112 formed thereon are removed. Also, the firstadhesive material 113 may be removed.

According to the above-mentioned steps, it is possible to fabricate asemiconductor device including the lamination body formed on the oxidefilm and the anti-reduction film, wherein the oxide film and theanti-reduction film are further provided on the flexible substrate,i.e., on the plastic substrate. By using plastic as a support medium, athin, lightweight, flexible semiconductor device can be manufactured.

Embodiment 1

In the present embodiment, a method of manufacturing a semiconductordevice using Embodiment Mode 1 will be described with reference to FIGS.3A to 3E and FIGS. 4A to 4D.

As shown in FIG. 3A, a metal film 302 (e.g., a tungsten film with athickness of 10 to 200 nm, preferably, 30 to 75 nm) is formed on a firstsubstrate 301. The metal film is heated to form an oxide film 303 (e.g.,a tungsten oxide film) with a thickness of 1 to 10 nm, preferably, 2 to5 nm.

Since the tungsten film and the tungsten oxide film are also formed onedge surfaces of the substrate by sputtering, they are preferably andselectively removed therefrom by O₂ ashing etc.

An anti-reduction film 304 is formed by sputtering. In the embodiment,an AlN_(x)O_(y) film is formed by using an aluminum nitride (AlN) targetunder an atmosphere of containing a mixture of argon gas, nitrogen gas,and oxygen gas. A first insulating film 305, e.g., a silicon oxynitridefilm, is next laminated by PCVD. An amorphous silicon film 306containing hydrogen is further laminated thereon without exposing it tothe atmospheric air.

The amorphous silicon film 306 is next crystallized by a known technique(e.g., solid phase growth, laser crystallization, crystallization usinga catalytic metal, and the like) so as to form a TFT using a polysiliconfilm as an active layer. In the present embodiment, the polysilicon filmis obtained by crystallization using a catalytic metal. A solution 307containing a metal element of 10 ppm by weight (which is, herein, anickel acetate solution) is applied by a spinner. As substitute for theapplication, a method of dispersing nickel elements on an entire surfaceof the amorphous silicon film by sputtering may be employed. The appliednickel acetate solution 307 and the first insulating film are heated andcrystallized to form a semiconductor film having a crystalline structure(that is a first polysilicon film 308 in FIG. 3B). In the embodiment,after a heat treatment for dehydrogenation is carried out (at 500° C.for one hour) to eliminate hydrogen, a heat treatment forcrystallization is performed (at 500° C. for four hours) so that asilicon film with a crystalline structure is obtained.

The other crystallization methods are, for example, cited as follows,and the following methods may arbitrarily be employed. After doping ametal element, which will serve as a catalyst, to an amorphous siliconfilm, the doped amorphous silicon film is heated to form a polysiliconfilm, and the polysilicon film is irradiated with pulsed laser beam.Another method is that an amorphous silicon film is irradiated withcontinuous wave laser so as to achieve a polysilicon film. Still anothermethod is that after heating an amorphous silicon film to form apolysilicon film, the resultant polysilicon film is irradiated withlaser beam. Yet another method is that an amorphous silicon film isdoped with a metal element, which will serve as a catalyst, and heatedto obtain a polysilicon film, and laser beam is irradiated to thepolysilicon film.

Since the films contacting to the oxide film 303 (i.e., the metal film302 and the anti-reduction film 304) do not contain hydrogen, they arenot reduced in the above step of heating the amorphous silicon film 306.Therefore, separation can be caused inside the tungsten oxide film or inan interface between the tungsten film and the tungsten oxide film laterby applying a relatively small force (e.g., hand power, gas pressureapplied through a nozzle, ultrasonic waves, load using a wedge-shapedmember, etc.).

After removing an oxide film formed on a surface of the silicon film 308with the crystalline structure by using diluted hydrofluoric acid etc.,the surface thereof is irradiated with laser beam 309 (XeCl with awavelength of 308 nm) in the atmospheric air or under an oxygenatmosphere so as to increase the degree of crystallinity and repair thedefects remaining in crystal grains so that a second polysilicon film310 is formed as shown in FIG. 3B.

As shown in FIG. 3C, an oxide film that is formed on a surface of thesecond polysilicon film 310 by laser irradiation is treated with ozonewater for 120 seconds to form a barrier film 311 made from an oxide filmwith a thickness of 1 to 5 nm in total. The barrier film 311 is formedto eliminate nickel, which has been doped for crystallization of theamorphous silicon film 306, from the polysilicon film. The oxide filmformed due to irradiation of laser beam may be removed prior to formingthe barrier film.

An amorphous silicon film 312 containing an argon element is next formedwith a thickness of 10 to 400 nm (e.g., 100 nm in the embodiment), whichwill serve as a gettering site, on the barrier film 311 by sputtering orPCVD.

Subsequently, the resultant substrate is heated for 3 minutes in afurnace that is heated at 650° C. to getter nickel so that the nickelconcentration contained in the semiconductor film with the crystallinestructure is reduced. A rump annealing apparatus may also be used, inplace of the furnace.

After selectively removing the amorphous silicon film 312 containing theargon element, which serves as the gettering site, by using the barrierfilm as an etching stopper, the barrier film is selectively removed bydiluted hydrofluoric acid, as shown in FIG. 3D. Since the nickel islikely to move to a region where the oxygen concentration is high uponthe gettering process, it is desirable that the barrier film made fromthe oxide film be removed after the gettering process.

When crystallization is carried out without using the catalytic element,the above-described steps for forming the barrier film, forming thegettering site, performing the heat treatment for gettering, removingthe gettering site, removing the barrier film, etc. are not required.

A thin oxide film is formed by using ozone water on a surface of a thusobtained silicon film with the crystalline structure (also referred toas a polysilicon film). A mask made from resist is then formed on thethin oxide film. The silicon film with the crystalline structure isetched into a predetermined shape to form island-like polysiliconregions 313 and 314 by using the mask. After forming the island-likepolysilicon regions, the mask made from the resist is removed.

After forming a second gate insulating film 319 covering the surface ofthe polysilicon regions 313, 314, gate electrodes 315 and 316 are formedthereon. An impurity element is doped to each active layer to form asource region and a drain region. An interlayer insulating film (aninorganic insulating film) is formed thereon. Source electrodes anddrain electrodes 317 a, 317 b, 318 a, and 318 b are formed. Anactivation treatment and a hydrogenation treatment are arbitrarilyperformed so that top-gate TFTs 320 and 321 using the polysilicon filmas their active layers are fabricated (FIG. 3E). When phosphorusimparting an n-type conductivity is doped to the active layer as animpurity element, an n-channel TFT can be formed. Alternatively, whenboron imparting a p-type conductivity is doped, a p-channel TFT can beformed. A CMOS circuit can be manufactured by combining the p-channelTFT and the n-channel TFT.

Note that although the embodiment exemplifies the top-gate TFTs as thestructure of the TFTs, the present embodiment is not particularlylimited to the structure. For instance, either inverted-stagger typeTFTs or stagger type TFTs may be employed. Also, an organicsemiconductor transistor, a diode, an MIM element and the like can beused as the semiconductor elements, in place of the TFTs.

Various kinds of semiconductor elements (such as a thin film diode and aresistive element) typified by the TFTs and sensor elements (typically,a pressure-sensitive fingerprint sensor using polysilicon) can be formedby utilizing the thus-obtained polysilicon regions.

A lamination body including the first insulating film and thesemiconductor elements 300 is thus formed.

Next, a photocatalytic layer 332 is formed on a glass substrate (i.e., atransparent substrate 331). In the embodiment, AN100 is used as theglass substrate. A TiOx layer is formed thereon by the sol-geltechnique.

As shown in FIG. 4A, a surface of the lamination body 300 is attached toa surface of the photocatalytic layer 332 by using a first adhesivematerial 333. An oil-soluble adhesive material is used as the firstadhesive material.

To perform the separation processing easily, a pretreatment is carriedout prior to the separation step, though not shown in the drawings. Ascriber device is used to move a hard needle while applying pressurewith press force of from 0.1 to 2 mm so that the edge surfaces of thesubstrate is removed in the embodiment. Consequently, the adhesivenessbetween the metal film 302 and the oxide film 303 is reduced. Byperforming the pretreatment of selectively (partly) reducing theadhesiveness in advance, poor separation can be prevented, therebyimproving the yield.

As shown in FIG. 4B, the lamination body 300 is separated from the firstsubstrate 301. That is, separation is caused between the metal film 302and the oxide film 303 by a physical means. The separation step can becarried out by a relatively small force (e.g., load using a member, handpower, gas pressure applied through a nozzle, ultrasonic waves, and thelike). In the embodiment, a part of a member having a sharp end such asa wedge is inserted between the metal film 302 and the oxide film 303 toseparate the two layers.

As shown in FIG. 4C, a second substrate 341 is attached to a surface ofthe oxide film 303 which is exposed due to the separation step by usinga second adhesive material 342. An epoxy resin is used as the secondadhesive material, while polycarbonate (PC) is used as the secondsubstrate.

Light 343 is next irradiated from a side of the transparent substrate331, which is the glass substrate. In this case, ultraviolet light isirradiated. By irradiating the ultraviolet light to the photocatalyticlayer 332, an oxidation-reduction reaction is caused in a portion of thefirst adhesive material 333 in contact with the photocatalytic layer 332and the organic resin, is decomposed so that the adhesive property ofthe adhesive material is reduced. Consequently, the photocatalytic layerand the glass substrate are separated from the first adhesive material333. Afterwards, the organic resin made from the oil-soluble resin issoaked in a solvent, e.g., ether, filled in a container to be dissolvedand removed (FIG. 4D).

If the adhesive material remains on the surface of the lamination body300, defects might be caused. Therefore, the surface thereof ispreferably washed by O₂ plasma irradiation, ultraviolet ray irradiation,ozone cleaning, etc. so as to remove the residue.

Thereafter, the substrate may be divided into respective circuitpatterns, properly. In the case of dividing a glass substrate or aquartz substrate into multiple patterns by using a scriber device, abreaker device, etc., breaking and cracking are easily caused.Therefore, it has been difficult to perform a process of dividing asubstrate into multiple pieces as the size of the pieces is reduced.However, the present invention uses a plastic film substrate instead ofthe glass substrate or the quartz substrate, and hence, the substratecan be easily divided into small-sized circuit patterns by laserprocessing or a cutter. Accordingly, microscopic devices can bemass-produced at high yield from a large-size substrate.

Note that although the present embodiment exemplifies the TFTs having asingle drain structure, the embodiment is not particular limitedthereto. A lightly doped drain (LDD) may be provided, if necessary, ormulti-channel TFTs having multiple channel forming regions, e.g.,double-gate TFTs may be used.

According to the invention, the lamination body can be separated at highyield without damaging the lamination body. Also, a semiconductor devicehaving a semiconductor element can be formed on a plastic substrate. Asa consequence, a lightweight, thin semiconductor device with anexcellent impact resistance property can be manufactured. In addition, asemiconductor device having a curved surface or a semiconductor devicethat can be varied in shape can be manufactured.

Embodiment 2

The present embodiment will explain a method of manufacturing asemiconductor device having an inverted-stagger type TFT with referenceto FIGS. 5A to 5D, and FIGS. 6A to 6E.

As shown in FIG. 5A, a metal film 302 with a thickness of 10 to 200 nm,preferably, 30 to 75 nm, an oxide film 303 with a thickness of 1 to 10nm, preferably, 2 to 5 nm, an anti-reduction film 304, and a baseinsulating film with a thickness of 100 nm are sequentially laminated ona first substrate 301 in the same manner as Embodiment 1. In the presentembodiment, a molybdenum film is formed as the metal film whereas amolybdenum oxide film is formed as the oxide film. As the anti-reductionfilm, a titanium nitride film having a conductive property is formed.

Subsequently, gate electrodes 506 and 507 are formed. For example, thegate electrodes may arbitrarily be formed as follows. After forming aconductive film by sputtering, vapor deposition, etc., the conductivefilm is etched into predetermined shapes to achieve the electrodes. Or,a solution containing conductive particles is sprayed onto predeterminedregions by the droplet discharging method and dried to achieve theelectrodes. As for the conductive film, a metal material such aschromium, molybdenum, titanium, tantalum, tungsten, aluminum, etc., oran alloy material thereof can be used. Since a first semiconductor film,a wiring film, and the like are formed on the gate electrodes, edges ofthe electrodes are desirably processed to have tapered shapes. When thegate electrodes 506 and 507 are made from an aluminum-based material,each surface thereof is preferably subjected to anodizing after etchingso as to insulate the respective surfaces. Note that a wiring forconnecting to the gate electrodes can simultaneously be formed in thestep, though not shown in the drawings.

A second insulating film 508, a first semiconductor film 509, and asecond semiconductor film 510 are next formed. By forming the secondinsulating film 508 on the gate electrodes 506 and 507, the secondinsulating film 508 can serve as a gate insulating film. In this case,the second insulating film 508 is preferably formed by laminating asilicon oxide film and a silicon nitride film. These insulating filmscan be formed by glow discharge decomposition or sputtering. Inparticular, in the case of forming dense insulating films with low gateleakage current at a low temperature, it is preferable that a reactivegas containing a rare gas element such as argon be mixed into theinsulating films.

The first semiconductor film 509 is made from a film containing asemiconductor with an intermediate structure between an amorphousstructure and a crystal structure (including a single crystal structureand a polycrystalline structure). The semiconductor includes a thirdcondition that is stable in terms of free energy and a crystallineregion having short-range order along with lattice distortion. That is,the semiconductor includes a Raman peak at the wavenumbers lower than520 cm⁻¹ according to the measurement of Raman spectrum. The averagesize of crystal grains is from 0.5 to 40 nm, and the crystal grains aredispersed in an amorphous semiconductor film. Further, the semiconductoris added with hydrogen or halogen of at least 1 atomic % or more as aneutralizing agent for dangling bonds. Such semiconductor having theabove-described properties is referred to as a semiamorphoussemiconductor (SAS). The SAS includes a so-called microcrystallinesemiconductor. By adding a rare gas element such as helium, argon,krypton, and neon to the SAS so as to promote the lattice distortion,the more stable, preferable SAS can be obtained. Such SAS is, forexample, disclosed in U.S. Pat. No. 4,409,134.

The SAS can be formed by glow discharge decomposition with silicide gas.As for the silicide gas, SiH₄, Si₂H₆, SiH₂Cl₂, SiHCl₃, SiCl₄, SiF₄, andthe like can be used. The silicide gas may also be diluted withhydrogen, or a mixture of hydrogen and one or more rare gas elementsselected from helium, argon, krypton, and neon so that the SAS can beformed easily. Preferably, the dilution ratio of the silicide gas is inthe range of from 1:10 to 1:1,000. The glow discharge decomposition is,of course, carried out under a reduced pressure to generate the SAS, andpressure may be approximately in the range of from 0.1 to 133 Pa. Thepower frequency is in the range of from 1 MHz to 120 MHz, preferablyfrom 13 MHz to 60 MHz. The high-frequency power may be set properly. Thesubstrate heating temperature is preferably set to 300° C. or less,preferably from 100 to 200° C. With respect to impurity elementscontained upon the film deposition, each concentration of impuritiesresulting from atmospheric constituents such as oxygen, nitrogen, andcarbon is preferably set to 1×10²⁰/cm³ or less. In particular, theoxygen concentration is set to 5×10¹⁹ atoms/cm³ or less; morepreferably, 1×10¹⁹ atoms/cm³ or less.

The silicide gas may also be mixed with carbide gas such as CH₄ and C₂H₆or germanium gas such as GeH₄ and GeF₄ to set the energy bandwidth inthe range of 1.5 to 2.4 eV, or 0.9 to 1.1 eV.

When an SAS is not added with an impurity element for controllingvalence electrons purposely, the SAS exhibits a weak n-type conductivitydue to impurities contained in the SAS. It is thought that oxygencontained in the SAS typically imparts the n-type conductivity to theSAS. The oxygen contained in the SAS is also changed depending on thehigh-frequency power density in the film deposition. In the invention,the oxygen concentration in the first semiconductor film 509 ispreferably set to 5×10¹⁹ atoms/cm³ or less, more preferably, 1×10¹⁹atoms/cm³ or less. Of course, all of the oxygen in the firstsemiconductor film does not serve as donor, and therefore, adequatedoses of an impurity element should be added to control the conductivitytype.

When an impurity element which imparts a p-type conductivity is added tothe first semiconductor film 509 to form a channel forming region ofTFTs at the same time as or after the deposition, a threshold voltagecan be controlled. Typically, boron is used as an impurity element forimparting the p-type conductivity. An impurity gas such as B₂H₆ and BF₃may be mixed into the silicide gas at a rate of 1 to 1,000 ppm. It ispreferable that the concentration of boron be 1×10¹⁴ to 6×10¹⁶atoms/cm³.

When forming n-channel TFTs, a second semiconductor film 510 may beadded with phosphorus as a typical impurity element. Specifically, animpurity gas such as PH₃ may be mixed into silicide gas. The secondsemiconductor film 510 may be formed of an SAS, an amorphoussemiconductor, or a microcrystalline semiconductor, so long as thevalence electrons are controlled.

The TFT manufactured above includes a structure, which can reduce theelectric-field concentration and the electro-current constriction whilethe channel forming region is not sandwiched between a source and adrain and between LDD regions.

As set forth above, the second insulating film 508, the firstsemiconductor film 509, and the second semiconductor film 510 having oneconductivity type can be successively formed without exposing them tothe atmospheric air. Accordingly, each layer can be formed withoutcontaminating each surface thereof with atmospheric constituents orimpurity elements existing in the atmosphere, thereby reducing variationin characteristics of TFTs.

Next, as shown in FIG. 5B, a mask is formed by using a photoresist. Byutilizing the mask, the first semiconductor film 509 and the secondsemiconductor film 510 having one conductivity type are etched to bepatterned like islands (i.e., a first island-like semiconductor film 512and a second island-like semiconductor film 513). Thereafter, the maskis removed. As substitute for the mask made from the photoresist, a maskmay be formed by spraying an organic resin in a predetermined regionusing the droplet discharging method. In the case of using the dropletdischarging method, the number of steps can be reduced since thephotolithography step is not required.

As shown in FIG. 5C, a mask (not shown) is formed on a predeterminedregion, and the second semiconductor film 510 having one conductivitytype is partly etched to form a disconnected second semiconductorregions 514 and 515, respectively. At this moment, the second insulatingfilm 508, which serves as a gate insulating film, and the firstinsulating film 305 are partly etched to form contact holes 516 a, 516b, 517 a, and 517 b so that the anti-reduction film 304 is partlyexposed.

As shown in FIG. 5D, wirings (source electrodes and drain electrodes 521a, 521 b, 522 a, and 522 b) connecting to a source region and a drainregion (i.e., the disconnected second semiconductor regions 514 and 515)are formed. The source and drain electrodes can be formed as follows:aluminum or an aluminum-based conductive material is formed and etchedinto predetermined shapes. Also, the source and drain electrodes mayhave lamination structures in which lower layers contacting to thesemiconductor film are made from titanium, tantalum, molybdenum, ornitrides thereof, and upper layers are made from the above mentionedaluminum or the aluminum-based conductive material. To improve the heatresistance properties, aluminum may be added with an element such astitanium, silicon, scandium, neodymium, and copper of 0.5 to 5 atomic %.Alternatively, the source and drain electrodes can be formed as follows:a solution containing conductive particles is sprayed onto predeterminedportions using the droplet discharging method and dried.

According to the above-described steps, channel-etched TFTs 523 and 524are formed.

Afterwards, an insulating film for protecting the channel forming regionis preferably formed of a silicon nitride film. A third insulating film525 is formed on the TFTs. It is preferable that the third insulatingfilm 525 be leveled and made from an organic resin such as acrylic,polyimide, and polyamide or an insulating film containing the Si—O bondand the Si—CHx bond. Subsequently, a second substrate 527 is attached tothe surface of the third insulating film 525 by using a first adhesivematerial 526.

The first insulating film 305, the TFTs 523, 524, the third insulatingfilm 525, the first adhesive material 526, and the second substrate 527are referred to as a lamination body 500.

A photocatalytic layer 332 is formed on a glass substrate (e.g., atransparent substrate 331) in the same manner as Embodiment 1. As shownin FIG. 6A, the surface of the photocatalytic layer 332 is attached tothe surface of the lamination body 500 by a second adhesive material333. As shown in FIG. 6B, the lamination body 500 is separated from thefirst substrate 301. Concretely, the metal film 302 is separated fromthe oxide film 303 by a physical means.

Subsequently, as shown in FIG. 6C, light 343 is irradiated from a sideof the transparent substrate 331 as well as Embodiment 1. Specifically,ultraviolet light is irradiated so that the photocatalytic layer and theglass substrate are separated from the second adhesive material. Thesecond adhesive material made from an oil-soluble resin is soaked in asolvent, e.g., ether that is filled in a container to dissolve andremove the adhesive material. If the adhesive material remains on thesurface of the lamination body 500, defects might be caused. Therefore,the surface thereof is preferably washed by O₂ plasma irradiation,ultraviolet ray irradiation, ozone cleaning, etc. so as to remove theresidue (FIG. 6D).

As shown in FIG. 6E, the oxide film 303 is removed by wet etching, andthe anti-reduction film 304 is then etched into predetermined shapes byusing a mask to form connection terminals 531 a, 531 b, 532 a, and 532b. A fourth insulating film is formed on the insulating film 305 and theconnection terminals 531 a, 531 b, 532 a, and 532 b. The fourthinsulating film is partly etched to form a protective film 533 whileexposing the respective connection terminals.

Thereafter, the resultant substrate may be divided in to respectivecircuit patterns. The present invention uses a plastic film substraterather than the glass substrate or the quartz substrate, and hence, thesubstrate can be easily divided into small-sized circuit patterns bylaser processing or a cutter. Accordingly, microscopic devices can bemass-produced at high yield from a large-size substrate.

Note that although the embodiment exemplifies the inverted-stagger typeTFTs, the present embodiment is not particularly limited to thestructure of the TFTs. For example, either top-gate TFTs or staggeredTFTs can be formed. As substitute for the TFTs, an organic semiconductortransistor, a diode, and an MIM element can be used as the semiconductorelements. Furthermore, the embodiment exemplifies the SAS as thesemiconductor film for the semiconductor element, however, the presentembodiment is not limited thereto. An amorphous semiconductor film or acrystalline semiconductor film as shown in Embodiment 1 can be employed.

According to the invention, the lamination body can be separated at highyield without damaging the lamination body. Further, a semiconductordevice including a semiconductor element can be formed on a plasticsubstrate. As the semiconductor device, a display device in which apixel driving element is formed of a semiconductor element, asemiconductor device chip in which a circuit is formed using asemiconductor element, and the like are exemplified. These semiconductordevices are lightweight and thin, and comprise the impact resistanceproperties. In addition, a semiconductor device having a curved surfaceor a semiconductor device that can be varied in shape can bemanufactured.

Embodiment 3

The present embodiment will describe a method of forming connectionterminals that is different from that of Embodiment 2 with reference toFIGS. 7A to 7E. Note that staggered TFTs are used for the sake ofexplanation. An anti-reduction film is made from an insulating film.

As shown in FIG. 7A, a metal film 302 with a thickness of 10 to 200 nm,preferably, 30 to 75 nm, an oxide film 303 with a thickness of 1 to 10nm, preferably, 2 to 5 nm, an anti-reduction film 304, and a baseinsulating film with a thickness of 100 nm are sequentially laminated ona first substrate 301 in the same manner as Embodiment 1. As theanti-reduction film, an AlN_(X)O_(Y) film is formed under an atmospherecontaining a mixture of argon gas and oxygen gas in the embodiment. TheAlN_(X)O_(Y) film may includes several atomic % or more of nitrogen,preferably, in the range of 2.5 to 47.5 atomic %. The concentration ofnitrogen can be controlled by arbitrarily adjusting the sputteringconditions (i.e., substrate temperature, raw material gas and its flowrate, film deposition pressure, and the like).

Subsequently, TFTs 607 and 608 are formed on the anti-reduction film304. The TFT 607 is formed as follows. Source and drain electrodes 601 aand 601 b are formed of a conductive material, and second semiconductorfilms 602 a, 602 b, a first semiconductor film 603, and a gateinsulating film 604 are sequentially laminated on the conductive layer.A gate electrode 605 is then formed to achieve the TFT 607. Similarly,the TFT 608 can be formed in the same manner as the TFT 607. Thus, theTFTs 607 and 608 (that includes the same structure as the TFT 607) canbe manufactured.

A first insulating film 606 is formed on the TFTs. The first insulatingfilm can be formed of the same material as the third insulating film ofEmbodiment 2. A second substrate 527 is next attached to the surface ofthe first insulating film 606 by using a first adhesive material 526.

The TFT 607, 608, the first insulating film 606, the first adhesivematerial 526, and the second substrate 527 are referred to as alamination body 600 (FIG. 7B).

A photocatalytic layer 332 is formed on a glass substrate (a transparentsubstrate 331) as well as Embodiment 1. A surface of the photocatalyticlayer 332 is attached to a surface of the lamination body 600 by using asecond adhesive material 333. As shown in FIG. 7B, the lamination body600 is separated from the first substrate 301. That is, the metal film302 is separated from the oxide film 303 by a physical means.

As shown in FIG. 7C, light 343 is irradiated from a side of thetransparent substrate 331 as well as Embodiment 1. In the presentembodiment, ultraviolet light is irradiated so that the photocatalyticlayer and the glass substrate are separated from the second adhesivematerial 333. Subsequently, the second adhesive material made from anoil-soluble resin is soaked in a solvent, e.g., ether that is filled ina container so that the second adhesive material is dissolved andremoved. If the adhesive material remains on the surface of thelamination body 600, defects might be caused. Therefore, the surfacethereof is preferably washed by O₂ plasma irradiation, ultraviolet rayirradiation, ozone cleaning, etc. so as to remove the residue (FIG. 7D).

As shown in FIG. 7E, the oxide film 303 and the anti-reduction film 304are etched into predetermined shapes by using a mask to form contactholes 612 a, 612 b, 613 a, and 613 b. The source and drain electrodes601 a, 601 b, 611 a, and 611 b are partly exposed to serve as connectionterminals. The etched oxide film and the anti-reduction film function asprotective films.

Afterwards, the resultant substrate is properly divided into respectivecircuit patterns.

Note that although staggered TFTs are used in the embodiment, theembodiment is not particularly limited to the structure. For example,inverted-stagger type TFTs or top-gate TFTs can be used. Assemiconductor elements, an organic semiconductor transistor, a diode,and an MIM element can be used, in place of the TFTs. Furthermore, thesemiconductor elements is formed using the SAS, however, the embodimentis not particularly limited thereto. For example, the semiconductorelements can be formed of an amorphous semiconductor film or thecrystalline semiconductor film as shown in Embodiment 1.

According to the invention, the lamination body can be separated at highyield without damaging the lamination body. Further, a semiconductordevice including the semiconductor elements can be formed on a plasticsubstrate. As the semiconductor device, a display device in which apixel driving element is formed of a semiconductor element, asemiconductor device chip in which a circuit is formed using asemiconductor element, and the like are cited. These semiconductordevices are lightweight and thin, and comprise the impact resistanceproperties. In addition, a semiconductor device having a curved surfaceor a semiconductor device that can be varied in shape can bemanufactured.

Embodiment 4

A semiconductor device that can be manufactured according to any one ofEmbodiments 1 to 3 will be described in the present embodiment withreference to a block diagram of FIG. 8, wherein one chip of a CPU 1000is illustrated.

When an operation code is inputted to a data bus interface 1001, thecode is decoded by an analysis circuit 1003 (also referred to as aninstruction decoder), and a signal is inputted to a control signalgeneration circuit 1004 (a CPU timing controller). Upon inputting thesignal, a control signal is output to an arithmetic logical unit 1009(hereinafter, an ALU) and a memory circuit 1010 (hereinafter, aregister) from the control signal generation circuit 1004.

The control signal generation circuit 1004 comprises an ALU controller1005 for controlling the ALU 1009 (hereinafter, ACON); a circuit 1006for controlling the register 1010 (hereinafter, a RCON), a timingcontroller 1007 for controlling timing (hereinafter, a TCON), and aninterruption controller 1008 for controlling interruption (hereinafter,an ICON).

On the other hand, when an operand is inputted to the interface 1001,the operand is outputted to the ALU 1009 and the register 1010. Then, aprocessing (such as a memory read cycle, a memory write cycle, an I/Oread cycle, and an I/O write cycle) based on the control signal, whichis inputted from the control signal generation circuit 1004, is carriedout.

The register 1010 includes a general register, a stack pointer (SP), aprogrammable counter (PC), and the like.

An address controller 1011 (hereinafter, ADRC) outputs 16 bits address.

A structure of the CPU described in this embodiment is illustrative onlyas a CPU manufactured according to the method of the present inventionand does not limit the structure of the present invention. Therefore, itis possible to use a known CPU with a structure other than that of thepresent embodiment.

Note that the present embodiment can be implemented by being freelycombined with Embodiment Mode 1 or 2.

Embodiment 5

The present embodiment will explain a method of mounting a semiconductordevice chip, e.g., a CPU with reference to FIGS. 19A to 19D. Themounting method may use the connection method with use of an anisotropicconductive adhesive material, the wire bonding method, and the like.Examples of the mounting methods will be described below.

FIG. 19A show an example in which a CPU 1703 is mounted on a wiringsubstrate 1701 by using an anisotropic conductive adhesive material1706. A wiring (now shown) and electrode pads 1702 a, 1702 b, which areextraction electrodes for the wiring, are formed on the wiring substrate1701.

Connection terminals 1704 a and 1704 b are provided on the surface ofthe CPU 1703, and a protective insulating film 1705 is formed in aperiphery thereof.

The CPU 1703 is fixed on the wiring substrate 1701 by an anisotropicconductive adhesive material 1706. The connection terminals 1704 a, 1704b and the electrode pads 1702 a, 1702 b are electrically connected toone another by conductive particles 1707 contained in the anisotropicconductive adhesive material. The anisotropic conductive adhesivematerial is an adhesive resin in which the conductive particles (with agrain size of 3 to 7 μm) are dispersed. An epoxy resin, a phenol resin,and the like can be cited as examples of the anisotropic conductiveadhesive material. The conductive particles (with a grain size ofseveral μm to several hundred μm) are made from an element selected fromgold, silver, copper, palladium, and platinum, or alloy particlesincluding the plural elements. Or, conductive particles formed bylaminating the above-mentioned elements may be used. Further, particlesin which resin particles are coated with one element selected from gold,silver, copper, palladium, and platinum, or an alloy containing theplural elements may also used.

As substitute for the anisotropic conductive adhesive material, it ispossible to use an anisotropic conductive film that is transferred on abase film. The conductive particles that are identical to those in theanisotropic conductive adhesive material are dispersed in theanisotropic conductive film. The size and density of the conductiveparticles 1707 mixed in the anisotropic conductive adhesive material1706 are adjusted adequately so that the CPU can be mounted on thewiring substrate as illustrated in FIG. 19A.

FIG. 19B shows an example of a mounting method that utilizes shrinkageof an organic resin. Barrier films 1711 a and 1711 b are formed on asurface of the connections terminals 1704 a and 1704 b of the CPU 1703by using Ta, Ti, and the like, and Au with a thickness of about 20 μm isformed thereon by electroless deposition so as to form bumps 1712 a and1712 b. The bumps are mounted on the CPU. When a light curableinsulating resin 1713 is interposed between the CPU and a wiringsubstrate 1701, the resin is cured by irradiating with light. Byutilizing the shrinkage of the resin that is cured due to irradiation oflight, the CPU can be mounted on the wiring substrate.

As shown in FIG. 19C, the CPU 1703 may be mounted on the wiringsubstrate 1701 as follows. The CPU 1703 is fixed on the wiring substrate1701 by using an adhesive material 1721, and the connection terminals1704 a, 1704 b of the CPU and the electrode pads 1702 a, 1702 b formedon the wiring substrate are connected to one another by Au wirings 1722a and 1722 b. The CPU is then sealed with an organic resin 1723.

As shown in FIG. 19D, a wiring 1732 on a FPC (flexible printed circuit)1731 is connected to an anisotropic conductive adhesive material 1706containing conductive particles 1708 so that the CPU 1703 may beprovided on the FPC. This structure is extremely effective in the caseof forming an electronic appliance that is limited in the size of ahousing such as a portable terminal.

Note that the method of mounting the semiconductor device is notparticularly limited to the above-described methods, and a known reflowprocessing with use of solder pumps can be performed. When performingthe reflow processing, it is preferable that a substrate of asemiconductor device is made from excellent heat-resistant plastic,typically, a polyimide substrate, a HT substrate (manufactured by NipponSteel Chemical Co., Ltd.), ARTON made from a norbornene resin with apolar radical (manufactured by JSR Corporation), and the like.

Embodiment 6

The present embodiment will explain a method of manufacturing a lightemitting display device that is one embodiment of a semiconductor devicewith reference to FIGS. 9A to 9D.

A lamination body 400 is formed on a first substrate 301 shown in FIG.3A in the same manner as Embodiment 1. As shown in FIG. 9A, a conductivefilm connecting to TFTs (p-channel TFTs) 320 and 321 is formed thereonand etched into a pixel size to form first pixel electrodes 401 and 402.In the embodiment, in order to form a top-emission type light emittingelement, the first electrodes 401 and 402 are formed of a conductivefilm with a light-shielding property, and TiN is used here. An insulator409 (also referred to as a bank, a partition wall, barrier, embankment,etc.) for covering edges of the first electrodes 401 and 402 is formedby a known method such as CVD, PVD, and application. The insulator 409can be made from an inorganic material (such as silicon oxide, siliconnitride, and silicon oxynitride); a photosensitive or nonphotosensitiveorganic material (such as polyimide, acrylic, polyamide, polyimideamide, resist, and benzocyclobutene); a lamination thereof; and thelike.

A layer 403 containing a luminescent substance is next formed by vapordeposition, application, ink-jet, etc. The layer containing theluminescent substance is formed by combining a hole injecting layer, ahole transporting layer, an electron injecting layer, and an electrontransporting layer, along with a light emitting layer. In addition, thelayer containing the luminescent substrate may be formed using any knownstructures. The light emitting layer may be formed of either an organicmaterial or an inorganic material. When the light emitting layer is madefrom an organic material, either a high molecular weight material or alow molecular weight material can be used. Preferably, degasification isperformed by vacuum heating prior to forming the layer 403 containingthe luminescent substance to improve the reliability. When using vapordeposition, for example, vapor deposition is carried out in a filmformation chamber, which is vacuum evacuated up to a level of 5×10⁻³Torr (0.665 Pa) or less, preferably, in the range of from 10⁻⁴ to 10⁻⁶Pa.

A second electrode 404 is formed on the layer 403 containing theluminescent substance. The second electrode is made from a transparentconductive film, and an ultra thin film of aluminum-lithium alloy is,herein, used.

Light emitting elements 405 and 406 include the first pixel electrodes401, 402, the layer 403 containing the luminescent substance, and thesecond electrode 404, respectively.

Subsequently, a second substrate 408 is attached to a surface of thesecond electrode 404 by a sealing material 407. As the sealing material,an epoxy resin is, herein, used. A transparent substrate 331 on which aphotocatalytic layer 332 is formed is attached to the surface of thesecond substrate 408 by using a first adhesive material 333.

As shown in FIG. 9B, the metal film 302 and the first substrate 301 areremoved from the oxide film 303.

As shown in FIG. 9C, a third substrate 341 is attached to the surface ofthe oxide film 303 by a third adhesive material 342. The secondsubstrate is made from polycarbonate, while the third adhesive materialis made from an epoxy resin in the embodiment.

Light 343, e.g., ultraviolet light, is irradiated from a side of thetransparent substrate 331. By irradiating the ultraviolet light to thephotocatalytic layer 332, an oxidation-reduction reaction is caused inthe second adhesive material that is in contact with the photocatalyticlayer to decompose the organic resin, reducing the adhesive property ofthe adhesive material. Consequently, the photocatalytic layer 332 andthe transparent substrate 331 are separated the second adhesive material333. Thereafter, the second adhesive material 333 made from anoil-soluble resin is soaked in a solvent, e.g., ether that is filled ina container so as to dissolve and remove the adhesive material. As aresult, a light emitting display device formed using the plasticsubstrate can be fabricated as shown in FIG. 9D.

In the case of forming a semiconductor device with light emittingelements that emit light toward the second substrate, i.e., upward, whenan anti-reduction film is formed of a material having a light-shieldingproperty, the anti-reduction film can serve as a light-shielding filmthat prevents outside light from intruding into the semiconductorelements. In this case, a semiconductor device having less failure ofthe semiconductor elements with high reliability can be manufactured.

In the case of forming a semiconductor device with light emittingelements that emit light downward or both upward and downward, i.e., atleast toward the third substrate 341, when the anti-reduction film isformed of a material having a light-shielding property, theanti-reduction film is preferably removed by etching.

The present embodiment can be applied to the steps of Embodiment Mode 2,in place of those of Embodiment Mode 1. Also, bottom-emission type lightemitting elements or dual-emission type light emitting elements can beformed as substitute for the top-emission type light emitting elements.In such case, the anti-reduction film should be made from a film havinga light-transmitting property. Or, the oxide film and the anti-reductionfilm having the light-shielding property must be removed to emit lightdownwardly.

According to the embodiment, a semiconductor device having semiconductorelements can be formed on a plastic substrate. That is, a display devicein which a pixel driving element is formed of a TFT can be fabricated.Such a semiconductor device is lightweight, thin and comprises anexcellent impact resistance property. In addition, a semiconductordevice with a curved surface or a semiconductor device that can bevaried in shape can be manufactured.

Embodiment 7

The present embodiment will describe structures of light emittingelements that are applicable to any one of Embodiment Modes 1, 2, and 6with reference to FIGS. 10A and 10B.

A light emitting element includes a pair of electrodes (i.e., an anodeand a cathode), and a layer containing a luminescent substance that issandwiched between the anode and the cathode. Hereinafter, firstelectrodes represent electrodes provided on the sides of theanti-reduction film of Embodiment Mode 1 and the second substrate ofEmbodiment Mode 2, whereas second electrodes represent electrodes thatare provided opposite of the anti-reduction film and the secondelectrode.

The layer containing the luminescent substance includes at least a lightemitting layer, and is formed by laminating one or more of layers havingdifferent properties with respect to carries such as a hole injectinglayer, a hole transporting layer, a blocking layer, an electrontransporting layer, and an electron injecting layer, along with thelight emitting layer.

FIGS. 10A and 10B show examples of cross sectional structures for lightemitting elements.

In FIG. 10A, a layer 1403 containing a luminescent substance is composedby sequentially laminating a hole injecting layer 1404, a holetransporting layer 1405, a light emitting layer 1406, an electrontransporting layer 1407, and an electron injecting layer 1408 on a firstelectrode (anode) 1401. A second electrode (cathode) 1402 is provided onthe electron injecting layer 1408 to complete a light emitting element.When a TFT for driving the light emitting element is provided in thefirst electrode (anode), a p-channel TFT is used as the TFT.

Meanwhile, in FIG. 10B, a layer 1413 containing a luminescent substanceis composed by sequentially laminating an electron injecting layer 1418,an electron transporting layer 1417, a light emitting layer 1416, a holetransporting layer 1415, and a hole injecting layer 1414 on a firstelectrode (cathode) 1411. A second electrode (anode) 1412 is provided onthe hole injecting layer 1414 to complete a light emitting element. Whena TFT for driving the light emitting element is provided in the firstelectrode (cathode), an n-channel TFT is used as the TFT.

Note that this embodiment is not limited to the above structures. Forexample, various types of structures can be employed for the lightemitting elements as follows: a structure of an anode/a hole injectinglayer/a light emitting layer/an electron transporting layer/and acathode; a structure of an anode/a hole injecting layer/a holetransporting layer/a light emitting layer/an electron transportinglayer/an electron injecting layer/and a cathode; a structure of ananode/a hole injecting layer/a hole transporting layer/a light emittinglayer/a hole blocking layer/an electron transporting layer/and acathode; a structure of an anode/a hole injecting layer/a holetransporting layer/a light emitting layer/a hole blocking layer/anelectron transporting layer/an electron injecting layer/and a cathode;and the like. Note that a stripe arrangement, a delta arrangement, amosaic arrangement and the like can be cited as the arrangement of alight-emitting region, i.e., the arrangement of a pixel electrode.

When the light emitting elements emit light upward, i.e., toward thesecond electrodes 1402 and 1412, respectively, the first electrodes 1401and 1411 are made from conductive films with light-shielding properties.In FIG. 10A, the first electrode 1401 serves as an anode, and hence, canbe formed of a single layer of TiN, ZrN, Ti, W, Ni, Pt, Cr, Al, etc., alamination layer in combination with a titanium nitride film and analuminum-based film, a three-layer structure of a titanium nitride film,an aluminum-based film, and another titanium nitride film, or the like.

In FIG. 10B, the first electrode 1411 serves as a cathode, andtherefore, can be formed of alkali metal (such as Li and Cs), alkaliearth metal (such as Mg, Ca, and Sr), an alloy containing the alkalimetal and alkali earth metal (such as Mg:Ag and Al:Li), or rare earthmetal (such as Yb and Er). In the case of using an electron injectinglayer made from LiF, CsF, CaF₂, Li₂O, or the like, a normal thinconductive film such as aluminum can be used as the first electrode.

The second electrodes 1402 and 1412 comprise polar characterscorresponding to the first electrodes 1401 and 1411, respectively, andare made from transparent conductive materials. In FIG. 10A, the secondelectrode 1402 serves as the cathode, and can be formed by laminating atransparent conductive film (ITO, IZO, ZnO, etc.) and an ultra thin filmcontaining alkali metal (such as Li and Cs) and alkali earth metal (suchas Mg, Ca, and Sr). Or, the second electrode 1402 may be formed byco-depositing an electron transporting material with alkali metal oralkali earth metal, and laminating a transparent conductive film (suchas ITO, IZO, and ZnO) thereon.

In FIG. 10B, the second electrode 1412 serves as the anode, and is madefrom a transparent conductive material such as indium-tin oxide (ITO)and indium-zinc oxide (IZO).

When the light emitting elements emit light downward, i.e., toward thefirst electrodes 1401 and 1411, the first electrodes 1401 and 1411 aremade from transparent conductive films. In FIG. 10A, the first electrode(anode) 1401 is formed of the above transparent conductive materials forthe anode. In FIG. 10B, the first electrode (cathode) 1401 is made fromthe above transparent conductive materials for the cathode.

The second electrode 1402 and 1412 comprise polar characterscorresponding to the first electrodes 1401 and 1411, respectively, andare made from conductive films having light-shielding properties. InFIG. 10A, the second electrode (cathode) 1402 is made from the abovematerials having the light-shielding properties for the cathode. In FIG.10B, the second electrode (anode) 1412 is made from the above materialshaving the light-shielding properties for the anode.

In FIGS. 10A and 10B, when the first electrodes 1401, 1411 and thesecond electrodes 1402, 1412 are formed of the above-mentionedtransparent conductive materials for the anodes and the above-mentionedtransparent conductive materials for the cathodes, respectively, lightcan be emitted toward both the first electrodes and the secondelectrodes.

The layers 1403 and 1413 containing the luminescent substances can beformed of conventional organic compounds such as a low molecular weightmaterial, a high molecular weight material, and a middle molecularweight material typified by oligomer, dendrimer, and the like. Also, alight emitting material (singlet compound) that emits light(fluorescence) by singlet excitation or a light emitting material(triplet compound) that emits light (phosphorescence) by tripletexcitation can be used.

Next, specific examples of materials for the layers 1403 and 1413containing the luminescent substances are shown below.

In the case of an organic compound, porphyrin compounds are effective asthe hole injecting materials for forming the hole injecting layers 1404and 1414, and phthalocyanine (hereinafter referred to as H₂-Pc), copperphthalocyanine (hereinafter, Cu-Pc), and the like can be used. As forthe hole injecting materials, there is also materials in whichconductive polymer compounds are subjected to chemical doping such aspolyethylene dioxythiophene (hereinafter, PEDOT) doped with polystyrenesulfonate (hereinafter, PSS), polyaniline (hereinafter, PAni), andpolyvinyl carbazole (hereinafter, PVK). It is also effective to use athin film made from an inorganic semiconductor such as vanadiumpentoxide or an ultra thin film made from an inorganic insulator such asaluminum oxide.

As hole transporting materials used for forming the hole transportinglayers 1405 and 1415, aromatic amine-based compounds (i.e., substanceshaving benzene ring-nitrogen bonds) are preferred. As the commonly-usedmaterials, for example, there areN,N′-bis(3-methylphenyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine(abbreviation: TPD); a derivative thereof such as4,4′-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (abbreviation: α-NPD);and the like. Further, star burst aromatic amine compounds such as 4,4′,4″-tris(N,N-diphenyl-amino)-triphenylamine (abbreviation: TDATA), and4,4′,4″-tris[N-(3-methylphenyl)-N-phenyl-amino]-triphenylamine(abbreviation: MTDATA) can also be cited.

Specific examples of the light emitting materials used for forming thelight emitting layers 1406 and 1416 include: metal complexes such astris(8-quinolinolate)aluminum (abbreviation: Alq₃),tris(4-methyl-8-quinolinolate)aluminum (abbreviation: Almq₃),bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviation: BeBq₂),bis(2-methyl-8-quinolinolate)-(4-hydroxy-biphenylyl)-aluminum(abbreviation: BAlq), bis[2-(2-hydroxyphenyl)-benzoxazolate]zinc(abbreviation: Zn(BOX)₂), andbis[2-(2-hydroxyphenyl)-benzothiazolate]zinc (abbreviation: Zn(BTZ)₂).In addition, various kinds of fluorescent dyes are effective for thematerial of the light-emitting layers. It is also possible to usetriplet luminescent materials in which complexes include platinum oriridium as their central metal. For example, the followings are known asthe triplet luminescent materials: tris(2-phenylpyridine) iridium(abbreviation: Ir(Ppy)₃);2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin-platinum (abbreviation:PtOEP); and the like.

As electron transporting materials for forming the electron transportinglayers 1407 and 1417, the following metal complexes can be cited:tris(8-quinolinolate)aluminum (abbreviation: Alq₃);tris(4-methyl-8-quinolinolate)aluminum (abbreviation: Almq₃);bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviation: BeBq₂);bis(2-methyl-8-quinolinolate)-(4-hydroxy-biphenylyl)-aluminum(abbreviation: BAlq); bis[2-(2-hydroxyphenyl)-benzoxazolate]zinc(abbreviation: Zn(BOX)₂); bis[2-(2-hydroxyphenyl)-benzothiazolate]zinc(abbreviation: Zn(BTZ)₂); and the like. In addition to the metalcomplexes, the electron transporting layers are made from materials asfollows: oxadiazole derivatives such as2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation:PBD), and 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene(abbreviation: OXD-7); triazole derivatives such as3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: TAZ), and3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole(abbreviation: p-EtTAZ); imidazole derivatives such as2,2′,2″-(1,3,5-benzenetriyl)tris[1-phenyl-1H-benzimidazole](abbreviation: TPBI); and phenanthroline derivatives such asbathophenanthroline (abbreviation: BPhen) and bathocuproin(abbreviation: BCP).

As electron injecting materials used for forming the electron injectinglayers 1408 and 1418, the above-mentioned electron transportingmaterials can be used. Besides, an ultra thin film made from aninsulator such as alkali metal halides (e.g., LiF and CsF), alkali earthhalides (e.g., CaF₂), and alkali metal oxides (e.g., Li₂O) is frequentlyused. In addition, alkali metal complexes such as lithiumacetylacetonate (abbreviation: Li(acac)) and 8-quinolinolate-lithium(abbreviation: Liq) can also be used effectively.

In the case of forming a light emitting display device according to thepresent embodiment, full color display can be achieved by making thelayer containing the luminescent substance to emit white light whileforming a color filter, additionally. Alternatively, full color displaycan be performed by making a layer containing a luminescent substance toemit blue light while providing a color conversion layer and the like,additionally.

Further, material layers emitting red, green, and blue lights,respectively, are formed in the layers 1403 and 1413 containing theluminescent substances so that full color display can be achieved. Alight emitting display device using a color filter exhibits high colorpurity of respective R, G, and B so that high definition display can beperformed.

Embodiment 8

Circuit diagrams of pixels for a light emitting display devicecorresponding to one embodiment of the semiconductor device according tothe invention will be described with reference to FIGS. 11A to 11C. FIG.11A is an equivalent circuit diagram of a pixel, including a signal line1514, a power supply lines 1515, 1517, a scanning line 1516, a lightemitting element 1513, a TFT 1510 for controlling input of video signalsto the pixel, a TFT 1511 for controlling the amount of current thatflows between electrodes, and a capacitor element 1512 for holding agate-source voltage. Although the capacitor element 1512 is shown inFIG. 11A, it may not be provided in the case where a gate capacitance orthe other parasitic capacitance can serve as a capacitor for holding thegate-source voltage.

FIG. 11B shows a pixel circuit having a structure in which a TFT 1518and a scanning line 1519 are additionally provided to the pixel shown inFIG. 11A. Supply of the current to the light emitting element 1513 canbe forcibly stopped due to the arrangement of the TFT 1518, therebystarting a lighting period simultaneously with or immediately after awriting period starts before signals are written in all of the pixels.Therefore, duty ratio is increased, and in particular, moving image canbe displayed favorably.

FIG. 11C shows a pixel circuit in which a TFT 1525 and a wiring 1526 areadditionally provided to the pixel shown in FIG. 11B. In the structure,a gate electrode of the TFT 1525 is connected to a wiring 1526maintaining a constant potential so that the potential for the gateelectrode is fixed. Further, the TFT 1525 is operated in a saturationregion. The TFT 1511 is connected to the TFT 1525 in series and operatedin a linear region. A gate electrode of the TFT 1511 is input with videosignals for transmitting information about lighting or non-lighting ofthe pixel via the TFT 1510. Since the source-drain voltage for the TFT1511 that is operated in the linear region is low, slight variation inthe gate-source voltage of the TFT 1511 does not adversely affect theamount of current flowing through the light emitting element 1513.Therefore, the amount of current flowing through the light emittingelement 1513 is determined by the TFT 1525, which is operated in thesaturation region. According to the invention having the above-mentionedstructure, luminance fluctuation of the light emitting element 1513,which is caused due to fluctuation in the characteristics of the TFT1525, can be reduced, thereby improving the image quality. It ispreferable that the channel length L₁ and the channel width W₁ for theTFT 1525, and the channel length L₂ and the channel width W₂ for the TFT1511 be set to satisfy the relation of L₁/W₁:L₂/W₂=5 to 6,000:1. It isalso preferable that the TFTs 1525 and 1511 comprise a same conductivitytype from the viewpoint of the manufacturing steps. The TFT 1525 may beeither an enhancement TFT or a depletion TFT.

In the light emitting display device of the invention, the method ofdriving screen display is not particularly limited. For example, a dotsequential driving method, a line sequential driving method, a surfacesequential driving method, and the like may be used. The line sequentialdriving method is typically used, and a time division gray scale drivingmethod or a surface area gray scale driving method may also be employedappropriately. Further, a source line of the light emitting displaydevice may be input with either analog signals or digital signals. Adriver circuit and the like may be designed properly according to theimage signals.

Light emitting display devices using digital video signals areclassified into one in which video signals are input to a pixel at aconstant voltage (CV), and another one in which video signals are inputto a pixel at a constant current (CC). The light emitting devices inwhich video signals are input to a pixel at a constant voltage (CV) arefurther classified into one in which a constant voltage is applied to alight emitting element (CVCV), and another one in which a constantcurrent is supplied to a light emitting element (CVCC). The lightemitting devices in which video signals are input to a pixel at aconstant current (CC) is still classified into one in which a constantvoltage is applied to a light emitting element (CCCV), and another onein which a constant current is supplied to a light emitting element(CCCC).

In the light emitting display device according to the invention, aprotection circuit (e.g., a protection diode and the like) may beprovided to the driver circuits or the pixel portion to inhibitelectrostatic discharge damage.

Embodiment 9

In the present embodiment, an exterior appearance of a light emittingdisplay device panel corresponding to one embodiment of thesemiconductor device according to the invention will be explained withreference to FIGS. 12A and 12B. FIG. 12A is a tow view of a panel inwhich a first substrate and a second substrate are sealed with a firstsealing material 1205 and a second sealing material 1206, while FIG. 12Bis a cross sectional view taken along a line A-A′ of FIG. 12A.

In FIG. 12A, reference numeral 1201 denoted by a doted line represents asignal line driver circuit; 1202, a pixel portion; and 1203, a scanningline driver circuit. In the embodiment, the signal line driver circuit1201, the pixel portion 1202, and the scanning line driver circuit 1203are positioned within a region sealed with the first and second sealingmaterials. As the first sealing material, an epoxy resin containingfiller with high viscosity is preferably used. As the second sealingmaterial, an epoxy resin having low viscosity is preferably used.Further, it is desirable that the first and second sealing materials1205, 1206 be materials that do not transmit moisture and oxygen as muchas possible.

Reference numeral 1240 denotes a connection wiring for transmittingsignals inputted in the signal line driver circuit 1201 and the scanningline driver circuit 1203, and receives video signals and clock signalsfrom an FPC (flexible printed circuit) 1209, which becomes an externalinput terminal, via a connection wiring 1208.

Next, a cross sectional structure will be described referring to FIG.12B. The first substrate 1200 is provided with driver circuits and apixel portion along with plural semiconductor elements typified by TFTs.As for the driver circuits, the signal line driver circuit 1201 and thepixel portion 1202 are illustrated. A CMOS circuit formed in combinationwith an n-channel TFT 1221 and a p-channel TFT 1222 is provided as thesignal line driver circuit 1201.

Since the TFTs of the signal line driver circuit, the scanning linedriver circuit, and the pixel portion are formed on the same substratein the present embodiment, the volume of the light emitting displaydevice can be reduced.

The pixel portion 1202 includes a plurality of pixels having a switchingTFT 1211, a driver TFT 1212, and a first electrode (anode) 1213 madefrom a conductive film with a light-shielding property, which iselectrically connected to a drain of the driver TFT 1212.

An interlayer insulating film 1220 of these TFTs 1211, 1212, 1221, and1222 may be formed of a material containing an inorganic material (suchas silicon oxide, silicon nitride, and silicon oxynitride) or an organicmaterial (such as polyimide, polyamide, polyimide amide,benzocyclobutene, and siloxane polymer) as its principal constituent.When the interlayer insulating film is formed of siloxane polymer, itbecomes to have a skeleton formed by the bond of silicon and oxygen andinclude hydrogen or/and alkyl group in a side chain.

An insulator (also referred to as a bank, a partition wall, a barrier,an embankment, etc.) 1214 is formed on each end of the first electrode(anode) 1213. To improve coverage of a film formed on the insulator1214, an upper edge portion or a lower edge portion of the insulator1214 is formed so as to have a curved surface having a radius ofcurvature. The insulator 1214 may be formed of a material containing aninorganic material (such as silicon oxide, silicon nitride, and siliconoxynitride) or an organic material (such as polyimide, polyamide,polyimide amide, benzocyclobutene, and siloxane polymer) as itsprincipal constituent. When the insulator is made from siloxane polymer,it becomes to have a skeleton formed by the bond of silicon and oxygenand include hydrogen or/and alkyl group in a side chain. Further, theinsulator 1214 may be covered with a protective film (a planarizinglayer) that is made from an aluminum nitride film, an aluminum nitrideoxide film, a thin carbon-based film, or a silicon nitride film.

An organic compound material is vapor deposited on the surface of thefirst electrode (anode) 1213 to form a layer 1215 containing aluminescent substance, selectively.

To remove gases contained in the substrate prior to performing the vapordeposition of the material for the layer containing the luminescentsubstance, a heat treatment at a temperature of 200 to 300° C. isdesirably carried out under a reduced pressure atmosphere or an inertatmosphere.

As for the layer 1215 containing the luminescent substance, thestructures as described in Embodiment 7 can be employed, arbitrarily.

In this way, a light emitting element 1217 including the first electrode(anode) 1213, the layer 1215 containing the luminescent substance, andthe second electrode (cathode) 1216 can be formed. The light emittingelement 1217 emits light toward the second substrate 1204.

A protective lamination layer 1218 is formed to encapsulate the lightemitting element 1217. The protective lamination layer is formed bylaminating a first inorganic insulating film, a stress relaxation film,and a second inorganic insulating film. The protective lamination layer1218 and the second substrate 1204 are attached to each other by usingthe first sealing material 1205 and the second sealing material 1206.The second sealing material is made of an adhesive agent 1219. Thesurface of the second substrate 1204 is fixed with a polarizing plate1225 using an adhesive material 1224. The surface of the polarizingplate 1225 is provided with a retardation plate 1229 of ½λ or ¼λ and anantireflection film 1226.

The connection wiring 1208 and the FPC 1209 are electrically connectedto one another with an anisotropic conductive film or an anisotropicconductive resin 1227, which is an anisotropic conductive adhesivematerial.

The light emitting display device using the plastic substrate accordingto the embodiment is lightweight and can exhibit an excellent impactresistance property.

Embodiment 10

In the present embodiment, an exterior appearance of a light emittingdisplay device panel corresponding to one embodiment of thesemiconductor device according to the invention will be explained withreference to FIGS. 13A and 13B. FIG. 13A is a top view of a panel inwhich a first substrate and a second substrate are attached to eachother by using a first sealing material 1205 and a second sealingmaterial 1206 formed on a protective lamination layer 1238. FIG. 13B isa cross sectional view taken along a line A-A′ of FIG. 13A. In theembodiment, an example in which a signal line driver circuit using an ICchip is mounted on the light emitting display device is shown.

In FIG. 13A, a reference numeral 1230 represents a signal line drivercircuit; 1202, a pixel portion; and 1203, a scanning line drivercircuit. Further, a reference numeral 1200 denotes the first substrate;reference numeral 1204 denotes the second substrate; and referencenumerals 1205, 1206 denote the first and second sealing materials thatcontain a gap material for maintaining a gap of an enclosed space,respectively.

The pixel portion 1202 and the scanning line driver circuit 1203 arepositioned inside a region sealed with the first and second sealingmaterials, while the signal line driver circuit 1230 is positionedoutside of the region sealed with the first and second sealingmaterials.

Next, a cross sectional structure will be described referring to FIG.13B. Driver circuits and a pixel portion are formed over the firstsubstrate 1200, which includes a plurality of semiconductor elementsrepresented by the TFTs. The signal line driver circuit 1230 that is oneof the driver circuits is connected to a terminal on an area 1210 withsemiconductor elements formed therein. The pixel portion 1202 isprovided on the first substrate. The signal line driver circuit 1230 ismade from an IC chip using a single crystal silicon substrate. Assubstitute for the IC chip using the single crystal silicon substrate,an integrated circuit chip formed by a TFT can be used. The pixelportion 1202 and the scanning line driver circuit (not shown in FIG.13B) are formed of TFTs. The pixel driving TFT and the scanning linedriver circuit are formed of inverted-stagger type TFTs, in theembodiment. A part or an entire of respective components for theinverted-stagger type TFTs can be formed by ink-jet, dropletdischarging, CVD, PVD, and the like.

A light emitting element 1237 includes a first electrode 1233, a layer1235 containing a luminescent substance, and a second electrode 1236.The electrodes and layer are formed using the same materials andmanufacturing methods of Embodiment 7. The light emitting element iselectrically connected to a TFT 1231 via a wiring 1232. Various kinds ofsignals and potential applied to the scanning line driver circuit 1203and the pixel portion 1202 are supplied from an FPC 1209 via connectionwirings 1208 and 1223. The connection wirings 1208, 1223 and the FPC1209 are electrically connected to one another with an anisotropicconductive film or anisotropic conductive resin 1227.

A polarizing plate 1225 is provided on the surface of the secondsubstrate 1204 as well as Embodiment 9. A retardation plate 1229 of ½λor ¼λ and an antireflection film 1226 are provided on the surface of thepolarizing plate 1225.

By using the plastic substrate, a lightweight light emitting displaydevice with an improved impact resistance property can be manufactured.

Embodiment 11

In the present embodiment, an exterior appearance of a liquid crystaldisplay device panel corresponding to one embodiment of thesemiconductor device according to the invention will be explained withreference to FIGS. 14A and 14B. FIG. 14A is a tow view of a panel inwhich a first substrate and a second substrate are attached to eachother by using a first sealing material 1605 and a second sealingmaterial 1606. FIG. 14B is a cross sectional view taken along a lineA-A′ of FIG. 14A.

In FIG. 14A, reference numeral 1601 denoted by a dotted line representsa signal line driver circuit; 1602, a pixel portion; and 1603, ascanning line driver circuit. In the present embodiment, the signal linedriver circuit 1601, the pixel portion 1602, and the scanning linedriver circuit 1603 are provided inside a region sealed with the firstand second sealing materials.

Further, reference numeral 1600 denotes the first substrate; and 1604,the second substrate. Reference numerals 1605 and 1606 represent thefirst and second sealing materials, respectively, that contain a gapmaterial for maintaining a gap of an enclosed space. The first substrate1600 and the second substrate 1604 are attached to each other by usingthe first and second sealing materials 1605, 1606, and a liquid crystalmaterial 1619 is filled therebetween.

A cross sectional structure will be described referring to FIG. 14B.Driver circuits and a pixel portion are formed on the first substrate1600 having multiple semiconductor elements typified by TFTs. A colorfilter 1621 is provided on a surface of the second substrate 1604. Thesignal line driver circuit 1601 and the pixel portion 1602 areillustrated as the driver circuits. The signal line driver circuit 1601includes a CMOS circuit in combination of an n-channel TFT 1612 and ap-channel TFT 1613.

The TFTs of the signal line driver circuit, the scanning line drivercircuit, and the pixel portion are formed on the same substrate in thepresent embodiment so that volume of the display device can be reduced.

A plurality of pixels is formed in the pixel portion 1602, and a liquidcrystal element 1615 is formed in each pixel. The liquid crystal element1615 indicates a portion overlapping a first electrode 1616, a secondelectrode 1618, and a liquid crystal material 1619, which is filledbetween the first and second electrodes, with one another. The firstelectrode 1616 of the liquid crystal element 1615 is electricallyconnected to the TFT 1611 via a wiring 1617. The second electrode 1618of the liquid crystal element 1615 is formed on a side of the secondsubstrate 1604. Note that an alignment film is formed on each surface ofrespective pixel electrodes, though not shown in the drawing.

Reference numeral 1622 represents a columnar spacer that is provided tomaintain a distance (cell gap) between the first electrode 1616 and thesecond electrode 1618. The spacer is formed by etching an insulatingfilm into a predetermined shape. Alternatively, a spherical spacer maybe employed. Various kinds of signals and potential are applied to thesignal line driver circuit 1601 and the pixel portion 1602 from an FPC1609 via a connection wiring 1608. The connection wiring 1608 and theFPC are electrically connected to one another with an anisotropicconductive film or anisotropic conductive resin 1627. Note that aconductive paste such as solder may be used in place of the anisotropicconductive film or anisotropic conductive resin.

A polarizing plate 1625 is fixed on the surface of the second substrate1604 by using an adhesive material 1624 as well as Embodiment 9. Acircular polarizing plate or an elliptical polarizing plate providedwith a retardation plate may be used as the polarizing plate 1625. Aretardation plate 1629 of ½λ or ¼λ and an antireflection film 1626 areprovided on the surface of the polarizing plate 1625. Similarly, thesurface of the first substrate 1600 is provided with a polarizing plate(now shown) by an adhesive material.

According to the embodiment, a liquid crystal display device having theplastic substrate can be fabricated. As a consequence, a lightweight,thin liquid crystal display device having an excellent impact resistanceproperty can be manufactured. In addition, a liquid crystal displaydevice having a curved surface and a liquid crystal display device thatcan be varied in shape can be manufactured.

Embodiment 12

In the present embodiment, an exterior appearance of a panelcorresponding to one embodiment of the semiconductor device according tothe invention will be explained with reference to FIGS. 15A and 15B.FIG. 15A is a top view of a panel in which a first substrate and asecond substrate are attached to each other by using a first sealingmaterial 1605 and a second sealing material 1606. FIG. 15B is a crosssectional view taken along a line A-A′ of FIG. 15A. An example in whicha signal line driver circuit using an IC chip is mounted on the panel isshown here.

In FIG. 15A, reference numeral 1630 represents a signal line drivercircuit; 1602, a pixel portion; and 1603, a scanning line drivercircuit. Further, reference numeral 1600 denotes the first substrate;and 1604, the second substrate. Reference numerals 1605 and 1606represent the first and second sealing materials, respectively, thatcontain a gap material for maintaining a cell gap of an enclosed space.

The pixel portion 1602 and the scanning line driver circuit 1603 areprovided inside a region sealed with the first and second sealingmaterials, whereas the signal line driver circuit 1630 is providedoutside of the region sealed with the first and second sealingmaterials. The first and second substrates 1600, 1604 are attached toeach other by the first and second sealing materials 1605, 1606, and aliquid crystal material is filled therebetween.

Next, a cross sectional structure will be described referring to FIG.15B. Driver circuits and a pixel portion are formed over the firstsubstrate 1600, which includes a plurality of semiconductor elementsrepresented by TFTs. The signal line driver circuit 1630 that is one ofthe driver circuits is connected to a terminal on the layer 1610 withthe semiconductor elements formed therein. The pixel portion 1602 isprovided over the first substrate. The signal line driver circuit 1630is made from an IC chip suing a single crystal silicon substrate. Assubstitute for the IC chip using the single crystal silicon substrate,an integrated circuit chip formed of a TFT can be used. The pixelportion 1602 and the scanning line driver circuit (not shown in FIG.15B) are formed of the TFTs. In the present embodiment, a pixel drivingTFT and a scanning line driver circuit are formed of inverted-staggertype TFTs, which are made from an amorphous semiconductor film or amicrocrystalline semiconductor film, as well as Embodiment 9.

A first electrode 1616 of the liquid crystal element 1615 iselectrically connected to a TFT 1631 via a wiring 1632 in the samemanner as Embodiment 11. A second electrode 1618 of the liquid crystalelement 1615 is formed on the second substrate 1604. Reference numeral1622 represents a columnar spacer, and is provided to maintain thedistance (cell gap) between the first electrode 1616 and the secondelectrode 1618. Various kinds of signals and potential are applied tothe scanning line driver circuit 1603 and the pixel portion 1602 from anFPC 1609 via connection wirings 1608 and 1623. The connection wirings1608 and 1623 and the FPC are electrically connected to one another withan anisotropic conductive film or anisotropic conductive resin 1627.

A polarizing plate 1625 is fixed on the surface of the second substrate1604 with an adhesive material 1624 in the same manner as Embodiment 9.A retardation plate 1629 of ½λ or ¼λ and an antireflection film 1626 areprovided on the surface of the polarizing plate 1625.

According to the embodiment, a liquid crystal display device having aplastic substrate can be fabricated. As a consequence, a lightweight,thin liquid crystal display device having an excellent impact resistanceproperty can be manufactured. Additionally, a display device having acurved surface and a display device that can be varied in shape can bemanufactured.

Embodiment 13

Various kinds of electronic appliances can be manufactured by beingincorporated with a semiconductor device formed according to the presentinvention. Examples of the electronic appliances include: a TV set; avideo camera; a digital camera; a goggle type display (a head-mounteddisplay); a navigation system; an audio reproduction device (such as acar audio and an audio component system); a personal laptop computer; agame machine; a portable information terminal (such as a mobilecomputer, a cellular telephone, a portable game machine, and anelectronic book); an image reproduction device provided with a recordingmedium (concretely, a device which can reproduce the recording mediumsuch as a digital versatile disc (DVD) and display images thereof); andthe like. As representative examples of these electronic appliances, ablock diagram and a perspective view of a television are shown in FIG.16 and FIG. 17, respectively, while perspective views of a digitalcamera are shown in FIGS. 18A and 18B.

FIG. 16 is a block diagram showing a general structure of a televisionthat receives analog television broadcasting. In FIG. 16, the airwavesfor television broadcasting received by an antenna 1101 are input in atuner 1102. The tuner 1102 generates and outputs intermediate frequency(IF) signals by mixing the high frequency television signals input bythe antenna 1101 and locally-oscillating frequency signals that arecontrolled in accordance with the predetermined reception frequency.

The IF signals output from the tuner 1102 are amplified up to therequired amount of voltage by an intermediate frequency amplifier (IFamplifier) 1103. Thereafter, the amplified IF signals are detected by animage detection circuit 1104 and an audio detection circuit 1105. Thesignals output from the image detection circuit 1104 are divided intoluminance signals and color signals by an image processing circuit 1106.Further, the luminance signals and the color signals are subjected tothe predetermined image signal processing to become image signals sothat the image signals are output to an image output unit 1108 such as aDMD (digital micromirror device), a PDP (plasma display panel), an FED(field emission display), and an electrophoretic display device (e.g.,an electronic paper).

The signals output from the audio detection circuit 1105 are subjectedto processing such as FM demodulation in an audio processing circuit1107 to become audio signals. The audio signals are then amplifiedarbitrarily so as to be output to an audio output unit 1109 such as aspeaker.

The television according to the present invention may be applicable todigital broadcastings such as digital terrestrial broadcasting, cabledigital broadcasting, and BS digital broadcasting, besides analogbroadcastings such as regular broadcasting in VHF band, in UHF band,etc., cable broadcasting, and BS broadcasting.

FIG. 17 is a perspective view seen from the front of the television,including a housing 1151; a display portion 1152; speaker units 1153; anoperational portion 1154; a video input terminal 1155; and the like. Thetelevision shown in FIG. 17 includes the structure as shown in FIG. 16.

The display portion 1152 is an example of the image output unit 1108 inFIG. 16, and displays images.

The speaker units 1153 are examples of the audio output unit in FIG. 16,and output sound therefrom.

The operational portion 1154 is provided with a power source switch, avolume switch, a channel select switch, a tuning switch, a selectionswitch, and the like so as to turn on and off the television, selectimages, control sound, select a tuner, and the like, respectively. Notethat above-mentioned selections and operations can also be carried outby a remote-control unit, though not illustrated in the drawing.

The video input terminal 1155 inputs image signals into the televisionfrom an external portion such as a VTR, a DVD, and a game machine.

In the case of a wall-mounted television, a hanging portion is providedon the rear of the body thereof.

By applying the display device that is an example of a semiconductordevice according to the invention to the display portion of thetelevision, a thin, lightweight television having an excellent impactresistance property can be manufactured. When a semiconductor deviceaccording to the invention is applied to a CPU for controlling an imagedetection circuit, an image processing circuit, an audio detectioncircuit, and an audio processing circuit of a television, a thin,lightweight television with an excellent impact resistance property canbe manufactured. Consequently, such a television is widely applicable towall-mounted televisions, in particular, to large-size display mediumssuch as information display boards used in railway stations, airports,etc., and advertisement display boards on the streets.

Next, an example in which the display device manufactured according tothe invention is applied to a digital camera will be described withreference to FIGS. 18A and 18B.

FIGS. 18A and 18B are diagrams showing an example of the digital camera.FIG. 18A is a perspective view seen from the front of the digitalcamera, while FIG. 18B is a perspective view seen from the rear thereof.In FIG. 18A, reference numeral 1301 represents a release button; 1302, amain switch; 1303, a viewfinder window; 1304, flash; 1305, a lens; 1306,a lens barrel; and 1307, a housing.

In FIG. 18B, reference numeral 1311 represents a viewfinder eyepiece;1312, a monitor; and 1313, an operational button.

Upon depressing the release button 1301 halfway, a focus adjustmentmechanism and an exposure adjustment mechanism are operated.Subsequently, depressing the release button all the way releases ashutter.

The digital camera is turned on or off by pressing or rotating the mainswitch 1302.

The viewfinder window 1303 is disposed above the lens 1305 on the frontface of the digital camera, and a shooting range and a focusing pointare checked through the viewfinder eyepiece 1311 as shown in FIG. 18Band the viewfinder window.

The flash 1304 is disposed at the upper portion of the front face forthe digital camera body. In the case of photographing a subject of thelow luminance level, when depressing the release button, the shutter isreleased to take the picture simultaneously with flushing a light.

The lens 1305 is attached to the front of the digital camera. The lensis made of a focusing lens, a zoom lens, and the like. An opticalshooting system includes the lens along with a shutter and an aperture,which are not illustrated in the drawing. An image pickup device such asa CCD (charge coupled device) is provided at the rear of the lens.

The lens barrel 1306 is used for shifting the lens position so as tofocus the focusing lens, the zoom lens, and the like on a subject. Totake the picture, the lens barrel is protruded from the body so that thelens 1305 is shifted toward a subject. When carrying the digital camera,the lens 1305 is stored inside the main body to be reduced in size. Notethat although the lens can be zoomed in to enlarge a subject by shiftingthe lens barrel in the present embodiment, the present embodiment is notlimited to the structure. The embodiment can be applicable to a digitalcamera that can take close-up pictures without zooming a lens due to astructure of an optical shooting system inside the housing 1307.

The viewfinder eyepiece 1311 is provided at the upper portion of therear of the digital camera, through which the shooting range and thefocusing point are checked by sight.

The operational button 1313 represents a button with various kinds offunctions and is provided on the rear of the digital camera. Theoperational button include a setup button, a menu button, a displaybutton, a functional button, a selection button, and the like.

By utilizing the display device that is one embodiment of asemiconductor according to the invention to a monitor of the digitalcamera, a thinner, portable digital camera can be manufactured. A CPUthat is an example of the semiconductor device according to theinvention can be applied to a CPU for processing in response to inputoperation of various functional buttons, a main switch, a release buttonetc., a CPU for controlling various circuits such as a circuit forautofocusing and autofocusing adjustment, a circuit for controllingelectric flash drive, a timing control circuit for CCD drive, an imagepickup circuit for generating a image signal from a signal that isconverted photoelectrically by an image pickup device such as a CCD, anA/D converter for converting an image signal generated in an imagepickup circuit into a digital signal, and a memory interface for writingand reading image data in a memory. The application of the inventionpermits fabrication of a thinner, portable digital camera.

The present invention has been fully described by way of embodimentmodes and embodiments with reference to the accompanying drawings. Notethat it should be understood to those skilled in the art that thepresent invention can be embodied in several forms, and the modes andits details can be changed and modified without departing from thepurpose and scope of the present invention. Accordingly, interpretationof the present invention should not be limited to descriptions mentionedin the foregoing embodiment modes and embodiments. Note that portionsidentical to each other are denoted by same reference numerals in theaccompanying drawings for the sake of convenience.

This application is based on Japanese Patent Application serial No.2003-414879 filed in Japan Patent Office on Dec. 12, 2003, the contentsof which are hereby incorporated by reference.

1. A method for manufacturing a semiconductor device comprising:providing a semiconductor element attached to a substrate with aphotocatalytic layer interposed therebetween; and peeling the substratefrom the semiconductor element by irradiating the photocatalytic layerwith a light.
 2. A method for manufacturing a semiconductor deviceaccording to claim 1, wherein the substrate is a glass substrate.
 3. Amethod for manufacturing a semiconductor device according to claim 1,wherein the substrate is attached over the semiconductor element.
 4. Amethod for manufacturing a semiconductor device according to claim 1,wherein the photocatalytic layer contains one selected from the groupconsisting of titanium oxide, titanate, tantalate, niobate, CdS, andZnS.
 5. A method for manufacturing a semiconductor device according toclaim 1, wherein the semiconductor element contains one selected fromthe group consisting of a thin film transistor, an organic semiconductortransistor, a diode, and an MIM element.
 6. A method for manufacturing asemiconductor device according to claim 1, wherein the semiconductordevice is one selected from the group consisting of a TV set, a videocamera, a digital camera, a goggle type display, a navigation system, anaudio reproduction device, a laptop computer, a game machine, a mobilecomputer, a cellular phone, an electronic book, and an imagereproduction device.
 7. A method for manufacturing a semiconductordevice comprising: providing a semiconductor element attached to asubstrate with a photocatalytic layer and an adhesive layer interposedtherebetween; and peeling the substrate from the semiconductor elementby irradiating the photocatalytic layer with a light.
 8. A method formanufacturing a semiconductor device according to claim 7, wherein thesubstrate is a glass substrate.
 9. A method for manufacturing asemiconductor device according to claim 7, wherein the substrate isattached over the semiconductor element.
 10. A method for manufacturinga semiconductor device according to claim 7, wherein the photocatalyticlayer contains one selected from the group consisting of titanium oxide,titanate, tantalate, niobate, CdS, and ZnS.
 11. A method formanufacturing a semiconductor device according to claim 7, wherein theadhesive layer contains one selected from the group consisting of anepoxy resin, a silicon resin, and an acrylic resin.
 12. A method formanufacturing a semiconductor device according to claim 7, wherein thesemiconductor element contains one selected from the group consisting ofa thin film transistor, an organic semiconductor transistor, a diode,and an MIM element.
 13. A method for manufacturing a semiconductordevice according to claim 7, wherein the semiconductor device is oneselected from the group consisting of a TV set, a video camera, adigital camera, a goggle type display, a navigation system, an audioreproduction device, a laptop computer, a game machine, a mobilecomputer, a cellular phone, an electronic book, and an imagereproduction device.
 14. A method for manufacturing a semiconductordevice comprising: providing a semiconductor element attached to asubstrate with a photocatalytic layer interposed therebetween; andpeeling the substrate from the semiconductor element by irradiating thephotocatalytic layer with a light from a side of the substrate.
 15. Amethod for manufacturing a semiconductor device according to claim 14,wherein the substrate is a glass substrate.
 16. A method formanufacturing a semiconductor device according to claim 14, wherein thesubstrate is attached over the semiconductor element.
 17. A method formanufacturing a semiconductor device according to claim 14, wherein thephotocatalytic layer contains one selected from the group consisting oftitanium oxide, titanate, tantalate, niobate, CdS, and ZnS.
 18. A methodfor manufacturing a semiconductor device according to claim 14, whereinthe semiconductor element contains one selected from the groupconsisting of a thin film transistor, an organic semiconductortransistor, a diode, and an MIM element.
 19. A method for manufacturinga semiconductor device according to claim 14, wherein the semiconductordevice is one selected from the group consisting of a TV set, a videocamera, a digital camera, a goggle type display, a navigation system, anaudio reproduction device, a laptop computer, a game machine, a mobilecomputer, a cellular phone, an electronic book, and an imagereproduction device.
 20. A method for manufacturing a semiconductordevice comprising: providing a semiconductor element attached to asubstrate with a photocatalytic layer and an adhesive layer interposedtherebetween; and peeling the substrate from the semiconductor elementby irradiating the photocatalytic layer with a light from a side of thesubstrate.
 21. A method for manufacturing a semiconductor deviceaccording to claim 20, wherein the substrate is a glass substrate.
 22. Amethod for manufacturing a semiconductor device according to claim 20,wherein the substrate is attached over the semiconductor element.
 23. Amethod for manufacturing a semiconductor device according to claim 20,wherein the photocatalytic layer contains one selected from the groupconsisting of titanium oxide, titanate, tantalate, niobate, CdS, andZnS.
 24. A method for manufacturing a semiconductor device according toclaim 20, wherein the adhesive layer contains one selected from thegroup consisting of an epoxy resin, a silicon resin, and an acrylicresin.
 25. A method for manufacturing a semiconductor device accordingto claim 20, wherein the semiconductor element contains one selectedfrom the group consisting of a thin film transistor, an organicsemiconductor transistor, a diode, and an MIM element.
 26. A method formanufacturing a semiconductor device according to claim 20, wherein thesemiconductor device is one selected from the group consisting of a TVset, a video camera, a digital camera, a goggle type display, anavigation system, an audio reproduction device, a laptop computer, agame machine, a mobile computer, a cellular phone, an electronic book,and an image reproduction device.
 27. A method for manufacturing asemiconductor device comprising: providing a semiconductor elementattached to a substrate with a photocatalytic layer interposedtherebetween; and peeling the substrate from the semiconductor elementby irradiating the photocatalytic layer with an ultraviolet light.
 28. Amethod for manufacturing a semiconductor device according to claim 27,wherein the substrate is a glass substrate.
 29. A method formanufacturing a semiconductor device according to claim 27, wherein thesubstrate is attached over the semiconductor element.
 30. A method formanufacturing a semiconductor device according to claim 27, wherein thephotocatalytic layer contains one selected from the group consisting oftitanium oxide, titanate, tantalate, niobate, CdS, and ZnS.
 31. A methodfor manufacturing a semiconductor device according to claim 27, whereinthe semiconductor element contains one selected from the groupconsisting of a thin film transistor, an organic semiconductortransistor, a diode, and an MIM element.
 32. A method for manufacturinga semiconductor device according to claim 27, wherein the semiconductordevice is one selected from the group consisting of a TV set, a videocamera, a digital camera, a goggle type display, a navigation system, anaudio reproduction device, a laptop computer, a game machine, a mobilecomputer, a cellular phone, an electronic book, and an imagereproduction device.
 33. A method for manufacturing a semiconductordevice comprising: providing a semiconductor element attached to asubstrate with a photocatalytic layer and an adhesive layer interposedtherebetween; and peeling the substrate from the semiconductor elementby irradiating the photocatalytic layer with an ultraviolet light.
 34. Amethod for manufacturing a semiconductor device according to claim 33,wherein the substrate is a glass substrate.
 35. A method formanufacturing a semiconductor device according to claim 33, wherein thesubstrate is attached over the semiconductor element.
 36. A method formanufacturing a semiconductor device according to claim 33, wherein thephotocatalytic layer contains one selected from the group consisting oftitanium oxide, titanate, tantalate, niobate, CdS, and ZnS.
 37. A methodfor manufacturing a semiconductor device according to claim 33, whereinthe adhesive layer contains one selected from the group consisting of anepoxy resin, a silicon resin and, an acrylic resin.
 38. A method formanufacturing a semiconductor device according to claim 33, wherein thesemiconductor element contains one selected from the group consisting ofa thin film transistor, an organic semiconductor transistor, a diode,and an MIM element.
 39. A method for manufacturing a semiconductordevice according to claim 33, wherein the semiconductor device is oneselected from the group consisting of a TV set, a video camera, adigital camera, a goggle type display, a navigation system, an audioreproduction device, a laptop computer, a game machine, a mobilecomputer, a cellular phone, an electronic book, and an imagereproduction device.